Extreme rainfall in Geoje, South Korea, dropped over 900 mm [1] of rain over two days during a rare weather event.
The storm is significant because it represents a statistical rarity for the region, described by officials as a "200-year" event, and broke several local records for precipitation intensity.
Weather officials reported that the rainstorm hit Geoje and nearby Tongyeong in South Gyeongsang Province. The peak hourly rainfall reached 124.5 mm [1], which ranks as the fourth highest hourly rainfall on record for the region [1]. Additionally, the storm maintained an intensity of more than 110 mm per hour for two consecutive hours [1].
Ju Sun-young, a forecaster for the Korea Meteorological Administration, said the event was an extreme downpour that would likely occur once every 200 years. Ju said the daily precipitation and peak hourly rainfall in Geoje broke previous extreme values.
Local reporting indicates the daily rainfall totals were the highest since Typhoon Rusa in 2002 [1]. Reporter Jang Ah-young said the amount of rain falling in a single day was the most since that 2002 typhoon.
The storm's intensity created a scenario where the volume of water falling in a short window exceeded the capacity of typical regional infrastructure. While the total two-day accumulation was vast, the hourly peaks provided the most immediate risk to the coastal province.
“The rain was characterized as a "200-year" extreme event.”
The occurrence of a '200-year' event indicates a level of precipitation that statistically should only happen once every two centuries. When such extreme weather patterns emerge, it often suggests that historical meteorological benchmarks are being challenged, potentially requiring a reassessment of flood defenses and urban planning in coastal regions like South Gyeongsang Province.
